DRAKHYSYS INFINITY ENGINE TILESET WORKBENCH V4 BMP UPDATE
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What this update adds
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The Tileset Workbench now exports the three standard Infinity Engine area
companion bitmap resources:

  <AREA>HT.BMP  - height map
  <AREA>LM.BMP  - daytime light map
  <AREA>SR.BMP  - search / walkability map

CREATE NEW AREA FROM PNG
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When you create a new area, the Workbench now exports:

  AREA.ARE
  AREA.WED
  AREA.TIS
  PVRZ page(s)
  AREAHT.BMP
  AREALM.BMP
  AREASR.BMP

Default BMP behavior:
- HT.BMP: valid 4-bit indexed bitmap, uniform midpoint height (index 8).
- LM.BMP: valid 8-bit indexed bitmap, neutral/full white lighting.
- SR.BMP: valid 4-bit indexed bitmap, search-map value 7 (walkable stone).

The BMP dimensions use the Infinity Engine search-map grid:
  width  = ceil(area pixel width / 16)
  height = ceil(area pixel height / 12)

Example:
  1408 x 1024 area -> 88 x 86 HT/LM/SR maps.

CLONE / RECONSTRUCT EXISTING AREA
---------------------------------
Three optional source fields were added:
- HT.BMP
- LM.BMP
- SR.BMP

Use AUTO-DETECT HT / LM / SR BESIDE ARE to find matching companion maps.
On export:
- supplied companion maps are copied byte-for-byte and renamed to the new area;
- any missing companion map is generated with the safe defaults above.

Installation
------------
1. Keep your current Workbench folder.
2. Make a backup (a V3 backup script is also included here).
3. Replace your current tileset_workbench.py with the V4 file in this ZIP.
4. Start it with START_TILESET_WORKBENCH.bat as before.

This patch intentionally does not replace your resource_tools.py,
drakhysys_tileset core package, Near Infinity files, or game resources.

Validation performed
--------------------
- Python source syntax: PASS.
- Generated 1408x1024 companion map dimensions: 88x86.
- HT output: 4-bit indexed BMP, 16-color palette.
- LM output: 8-bit indexed BMP, 256-color palette.
- SR output: 4-bit indexed BMP, 16-color BG2 search palette.
- Source AR0015 HT/LM/SR copy-and-rename test: PASS.
